A 45-year-old woman with a 2-year history of systemic lupus erythematosus presents to the clinic with progressive dyspnea on exertion and lower extremity edema. Vital signs show BP 128/82 mmHg, HR 92 bpm, and RR 18. Cardiac auscultation reveals a holosystolic murmur best heard at the left lower sternal border that becomes louder with inspiration. Echocardiography demonstrates right ventricular dilatation with severe tricuspid regurgitation and elevated right ventricular systolic pressure. Which of the following best explains the inspiratory accentuation of the tricuspid regurgitation murmur?

1. A)Increased left ventricular afterload during inspiration causes rightward septal shift, worsening tricuspid coaptation
2. B)Decreased intrathoracic pressure during inspiration increases venous return to the right heart, increasing right ventricular stroke volumeGABARITO
3. C)Decreased pulmonary vascular resistance with inspiration reduces right ventricular afterload and increases flow across the tricuspid valve
4. D)Inspiration causes leftward deviation of the interventricular septum, directly increasing tricuspid leaflet excursion
5. E)Positive airway pressure during inspiration directly compresses the right atrium, increasing regurgitant flow